1. Technical Field
Embodiments of the present invention relate to a liquid crystal device for displaying various types of information and also relate to an electronic apparatus including the liquid crystal display.
2. Related Art
Examples of liquid crystal display modes include twisted nematic (TN) modes, vertical alignment modes for achieving a wide viewing angle and a high contrast ratio, transverse electric field modes such as an in-plane switching (IPS) mode and a fringe field switching (FFS) mode.
In the EPS mode, electric fields are applied to liquid crystal molecules in parallel to substrates. The IPS mode is superior to the TN mode in that a wide viewing angle can be achieved.
In general, an IPS-mode liquid crystal device includes pixel electrodes made of a transparent conductive material such as indium tin oxide (ITO) and common electrodes for generating transverse electric fields in cooperation with the pixel electrodes and the pixel and common electrodes are arranged in a single layer. Hence, there is a problem in that liquid crystal molecules located above the pixel electrodes cannot be sufficiently driven and this causes a reduction in transmittance.
On the other hand, in an FFS-mode liquid crystal device, a layer having common electrodes is overlaid with a layer having pixel electrodes with an interlayer insulating layer lying between these layers. Hence, electric fields can be applied transversely to liquid crystal molecules located above these pixel electrodes and therefore these pixel electrodes can be sufficiently driven. Thus, the FFS-mode liquid crystal device is superior in transmittance to the IPS-mode liquid crystal device.
JP-A-2001-235763 (hereinafter referred to as Patent Document 1) and JP-A-2002-182230 (hereinafter referred to as Patent Document 2) disclose FFS-mode liquid crystal devices.
The FFS-mode liquid crystal devices include amorphous-silicon thin-film transistors (a-Si TFTs).
The FFS-mode liquid crystal devices have a problem that when an insulating layer located between common electrodes and pixel electrodes has a reduced thickness such that auxiliary capacitors can be readily formed using the insulating layer and such that the level of image signals can be reduced by increasing the intensity of electric fields generated between the common and pixel electrodes, the common and pixel electrodes can be short-circuited depending on the layout of the common and pixel electrodes.